While the great majority of the one-year-old Dsg20/wt and Dsg2mt/wt mice did not develop the typical histomorphological ARVC phenotype detected in heart-specific Dsg2 knockout or homozygous Dsg2MT mice [42,48,50], the genetic predisposition for ARVC was revealed by some one-year-old Dsg20/wt mice with small fibrotic lesions accompanied by an inflammatory infiltrate and CX43 mislocation in lesion-near cardiomyocytes. This evidence concerns the gene GJA1 and Arrhythmogenic right ventricular dysplasia.